[Refactor] Use attributes to mark function as invalid for polly

  + Test case annotated with the new attribute
  + Modified test case to check if subfunctions are annotated

llvm-svn: 213093

6 files changed, 63 insertions, 15 deletions

diff --git a/polly/include/polly/ScopDetection.h b/polly/include/polly/ScopDetection.h
index e62db9321ff..96eeaef3d66 100644
--- a/polly/include/polly/ScopDetection.h
+++ b/polly/include/polly/ScopDetection.h
@@ -108,6 +108,9 @@ typedef std::map<const SCEVUnknown *, const SCEV *> BaseToElSize;
 extern bool PollyTrackFailures;
 extern bool PollyDelinearize;
 
+/// @brief A function attribute which will cause Polly to skip the function
+extern llvm::StringRef PollySkipFnAttr;
+
 //===----------------------------------------------------------------------===//
 /// @brief Pass to detect the maximal static control parts (Scops) of a
 /// function.
@@ -146,10 +149,6 @@ class ScopDetection : public FunctionPass {
   // Remember a list of errors for every region.
   mutable RejectLogsContainer RejectLogs;
 
-  // Remember the invalid functions producted by backends;
-  typedef std::set<const Function *> FunctionSet;
-  FunctionSet InvalidFunctions;
-
   // Delinearize all non affine memory accesses and return false when there
   // exists a non affine memory access that cannot be delinearized. Return true
   // when all array accesses are affine after delinearization.
@@ -249,13 +248,9 @@ class ScopDetection : public FunctionPass {
   /// @return True if the loop is valid in the region.
   bool isValidLoop(Loop *L, DetectionContext &Context) const;
 
-  /// @brief Check if a function is an OpenMP subfunction.
-  ///
-  /// An OpenMP subfunction is not valid for Scop detection.
-  ///
-  /// @param F The function to check.
+  /// @brief Check if the function @p F is marked as invalid.
   ///
-  /// @return True if the function is not an OpenMP subfunction.
+  /// @note An OpenMP subfunction will be marked as invalid.
   bool isValidFunction(llvm::Function &F);
 
   /// @brief Print the locations of all detected scops.
@@ -347,7 +342,7 @@ public:
   ///        the function.
   ///
   /// @param F The function to mark as invalid.
-  void markFunctionAsInvalid(const Function *F) { InvalidFunctions.insert(F); }
+  void markFunctionAsInvalid(Function *F) const;
 
   /// @brief Verify if all valid Regions in this Function are still valid
   /// after some transformations.
diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp
index 53c5ed791fb..f061f0149a8 100644
--- a/polly/lib/Analysis/ScopDetection.cpp
+++ b/polly/lib/Analysis/ScopDetection.cpp
@@ -136,6 +136,7 @@ static cl::opt<bool>
 
 bool polly::PollyTrackFailures = false;
 bool polly::PollyDelinearize = false;
+StringRef polly::PollySkipFnAttr = "polly.skip.fn";
 
 //===----------------------------------------------------------------------===//
 // Statistics.
@@ -769,8 +770,12 @@ bool ScopDetection::isValidRegion(DetectionContext &Context) const {
   return true;
 }
 
+void ScopDetection::markFunctionAsInvalid(Function *F) const {
+  F->addFnAttr(PollySkipFnAttr);
+}
+
 bool ScopDetection::isValidFunction(llvm::Function &F) {
-  return !InvalidFunctions.count(&F);
+  return !F.hasFnAttribute(PollySkipFnAttr);
 }
 
 void ScopDetection::printLocations(llvm::Function &F) {
diff --git a/polly/lib/CodeGen/LoopGenerators.cpp b/polly/lib/CodeGen/LoopGenerators.cpp
index 52a47ef578b..432960d2b85 100644
--- a/polly/lib/CodeGen/LoopGenerators.cpp
+++ b/polly/lib/CodeGen/LoopGenerators.cpp
@@ -229,7 +229,7 @@ Function *OMPGenerator::createSubfunctionDefinition() {
   Function *FN = Function::Create(FT, Function::InternalLinkage,
                                   F->getName() + ".omp_subfn", M);
   // Do not run any polly pass on the new function.
-  P->getAnalysis<polly::ScopDetection>().markFunctionAsInvalid(FN);
+  FN->addFnAttr(PollySkipFnAttr);
 
   Function::arg_iterator AI = FN->arg_begin();
   AI->setName("omp.userContext");
diff --git a/polly/test/Cloog/CodeGen/OpenMP/invalidate_subfn_scops.ll b/polly/test/Cloog/CodeGen/OpenMP/invalidate_subfn_scops.ll
index 6e75fe89702..b4eec09871c 100644
--- a/polly/test/Cloog/CodeGen/OpenMP/invalidate_subfn_scops.ll
+++ b/polly/test/Cloog/CodeGen/OpenMP/invalidate_subfn_scops.ll
@@ -1,4 +1,4 @@
-; RUN: opt %loadPolly %defaultOpts -polly-codegen -enable-polly-openmp -analyze < %s 2>&1 | not FileCheck %s
+; RUN: opt %loadPolly %defaultOpts -polly-codegen -enable-polly-openmp -analyze < %s 2>&1 | FileCheck %s
 
 ;#define N 500000
 ;float A[N];
@@ -47,4 +47,4 @@ for.end11:                                        ; preds = %for.inc8
 }
 
 
-; CHECK: Checking region: omp.setup
+; CHECK-NOT: Checking region: omp.setup
diff --git a/polly/test/Cloog/CodeGen/OpenMP/simple_nested_loop.ll b/polly/test/Cloog/CodeGen/OpenMP/simple_nested_loop.ll
index 1f4d68a81c7..27cecf2aa05 100644
--- a/polly/test/Cloog/CodeGen/OpenMP/simple_nested_loop.ll
+++ b/polly/test/Cloog/CodeGen/OpenMP/simple_nested_loop.ll
@@ -86,3 +86,7 @@ declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind
 ; CHECK: call void @loop_openmp.omp_subfn(i8* %omp_data)
 ; CHECK: call void @GOMP_parallel_end()
 
+; Verify the new subfunction is annotated such that SCoP detection will skip it.
+; CHECK: @loop_openmp.omp_subfn({{.*}}) [[ATTR:#[0-9]+]]
+; CHECK: attributes [[ATTR]] = {{{[^\}]*}}polly.skip.fn{{[^\}]*}}}
+
diff --git a/polly/test/ScopDetect/skip_function_attribute.ll b/polly/test/ScopDetect/skip_function_attribute.ll
new file mode 100644
index 00000000000..9d181fe51f4
--- /dev/null
+++ b/polly/test/ScopDetect/skip_function_attribute.ll
@@ -0,0 +1,44 @@
+; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s
+;
+; Verify polly skips this function
+;
+; CHECK-NOT: Valid Region for Scop
+;
+;    void polly_skip_me(int *A, int N) {
+;      for (int i = 0; i < N; i++)
+;        A[i] = A[i] * A[i] + A[i];
+;    }
+;
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-n32-S64"
+
+define void @polly_skip_me(i32* %A, i32 %N) #0 {
+entry:
+  br label %entry.split
+
+entry.split:                                      ; preds = %entry
+  %cmp1 = icmp sgt i32 %N, 0
+  br i1 %cmp1, label %for.body.preheader, label %for.end
+
+for.body.preheader:                               ; preds = %entry.split
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %i.02 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32* %A, i32 %i.02
+  %tmp = load i32* %arrayidx, align 4
+  %mul = mul nsw i32 %tmp, %tmp
+  %add = add nsw i32 %mul, %tmp
+  %arrayidx3 = getelementptr inbounds i32* %A, i32 %i.02
+  store i32 %add, i32* %arrayidx3, align 4
+  %inc = add nsw i32 %i.02, 1
+  %cmp = icmp slt i32 %inc, %N
+  br i1 %cmp, label %for.body, label %for.end.loopexit
+
+for.end.loopexit:                                 ; preds = %for.body
+  br label %for.end
+
+for.end:                                          ; preds = %for.end.loopexit, %entry.split
+  ret void
+}
+
+attributes #0 = { "polly.skip.fn" }